Hey MacRumors, I've been using Yosemite since the beta and I have send multiple messages to the feedback assistant but with every new update I lost hope that these issues would be addressed. So here's hoping some Apple devs read these forums. These are issues that prevents anyone in the audio/music scene from using Yosemite. A lot of these issues have also been experienced by my friends who updated. I'm a student at a conservatory specialized in producing music / recording audio and some of us have updated. (I know we probably should have waited a bit but that's not the point) Here's a list: -Most of the time the volume knobs don't work. I have to manually change the volume via system preferences. This happens the most when I unplug an external sound card and return to the built-in output but will also happen when I'm plugging in a stereo jack. -My balance (panning) is set slightly to the left at random. Really annoying as it's hard to notice but it alters you're judgement when producing/mixing. -I can't change sound cards in real time. I have to restart my mac in order to make the system change sound cards. -Whenever I open Logic Pro while listening to music on iTunes/Preview, it changes the sample rate of the song I am listening to to the one I am working on in Logic. In other words, the entire song is pitched up/down. -Sometimes the audio engine just suddenly stops working. (Could be a third party driver issue though) Well, as you can see these are all deal breakers for anyone working in the professional audio/music scene. DJ's using MacBooks won't be updating as well as Protools/Logic based studio's. Or maybe me and my fellow students just had bad luck. I don't know, but I really hope this will be fixed in the next update because beside this I really love Yosemite.